Add db-migration, create admin_unit table and foreign key.
Add upgrade step to create IAdminUnitConfiguration registry entry.
TMP: Dropped no longer used contact info method `list_assigned_users`.
Add sql-builders.

Move existing builders to builders package.
Display only current admin unit's users on the sharing view.

Old behavior was to use the client's users.
Replace ContactInformation is_one_client_setup with ogds service.